Figures from commercial farming show true sustainability of bioenergy

Is bioenergy sustainable or not? A question that keeps coming up, often getting contradictory answers. Applied Plant Research provides the answer by computing all direct and indirect effects of biomass cultivation.

Various aspects are playing a role in assessing the sustainability of bioenergy. An important aspect, e.g., is whether the cultivation of biomass for energy displaces the cultivation of food crops and thus increases the price of food. But sustainability of such a cultivation itself is playing a role as well: which amounts of pesticides, fertilisers and energy does a crop require and how large is the corresponding greenhouse gas emission.

Including indirect energy consumption

Direct energy consumption, such as fuel use during cultivation, is not the only factor to be taken into account when assessing the sustainability of a cultivation but indirect consumption needs to be considered as well. Production of the tractor needed for sowing and harvesting of the crop, for instance, also requires energy.

Measuring sustainability

The scientists have listed all these aspects of bioenergy for three existing bioenergy chains. For each of these chains the growers recorded all relevant data. And the researchers conducted measurements on the farms and at the processing companies.
They did this for:

Sugar beet fermented together with their foliage
Maize being co-fermented
Oilseed rape of which the oil is processed into pure vegetable oil or biodiesel

All three chains show a considerably lower greenhouse gas emission in comparison with the use of fossil energy. And the production of all three forms of bio-energy also yielded more energy than the amount used as input. For maize and sugar beet the energy output was about eight times the input and for oilseed rape this was four times.

Best practices biomass cultivation

Such computations not only allow the efficiency to be calculated. It is also possible to show how growers can make their cropping more sustainable. This has already led to a manual with best practices for the three crops.

Such sustainability computations can also be made for other bioenergy chains as well as for complete regions.